All, that is, except for Amanda Knox's defamation charge: That count -- with its 3-year prison sentence -- was upheld.

Why? Italy's defamation laws are different than the defamation laws we have stateside.

In the U.S., defamation is a civil matter. People sue each other alleging libel or slander in order to get monetary damages in civil court.

Not so in Italy, where defamation can be a criminal charge that carried jail time.

Knox was indicted for criminal defamation after she accused club owner Patrick Lumumba of murdering Meredith Kercher. Lumumba was eventually cleared of all charges after witnesses corroborated his alibi.

In Italy, defamation occurs when a person intends to use offensive language to harm another's reputation. It's also classified as a "crime against honor."

Would Knox's words be considered "defamation" in America? The required elements for defamation here are that:

A statement was made.

The statement was "published" to another.

The statement caused injury.

The statement was false.

The statement was unprivileged.

So if Knox's statements about Lumumba were true, she would have been able to use truth as a defense against defamation. Or, if she had testified about Lumumba during her trial, she may have had immunity for those statements since they would be considered "privileged."

Even if she had no defense against the accusatory statements she made towards Lumumba, under American law she likely wouldn't have faced jail time for slandering the club owner.

Unfortunately for Amanda Knox, defamation law works differently in Italy. But she likely isn't going to complain too loud on that point. Even though the defamation conviction was upheld, Knox was ordered freed from jail. She was sentenced to 3 years for the statements she made about Lumumba and has already spent 4 years behind bars. There is no word yet on whether the prosecutors in Knox's case will appeal the decision to Italy's highest court.